Fluid actuated injection means



Nov. 21, 1950 L. J. GARDAY FLUID ACTUATED INJECTION umms 3 Sheets-Sheet 1 Filed Oct. 22, 1947 Nov. 21, 19% L. J. GARDAY FLUID ACTUATED INJECTION MEANS 3 Sheets-Sheet 2 Filed Oct. 22, 1947 I l I Patented Nov. 21, 1950 2,53La 32 FLUID AGTUATED INJECTION MEANS Louis J. Gal-day, Glenvicw, Ill., asslgnor, by mesne assignments, to Louis G. Simmons, Chicago, Ill.

Application October 22, 1947, Serial No. 781,427

16 Claims.

vide an improved fuel injector for an internal combustion engine wherein fuel from a source under pressure performs the injection ofa-positively metered quantity of fuel.

It is a further object of the invention'to provide a fuel injector of the character indicated embodying a metering chamber and improved means for filling the metering chamber from a high pressure source of fuel.

It is a further object of the invention to provide a fuel injector of the character indicated embodying improved means for regulating the capacity of the fuel metering chamber.

It is a further object of the invention to provide a fuel injector of the character indicated embodying improved fuel injection valve actuation means.

It is a further object of the invention to provide a fuel injector of the character indicated embodying improved means for varying the timing of fuel injection.

Fora more complete understanding of the invention, referenceshould be had to the accompanying drawings in which:

Fig. l is a plan view partially broken away and partially in section of a fuel injector embodying the invention;

Fig. 2 is a fragmentary front elevational view partially in section of Fig. 1;

Fig. 3 is a sectional elevational view taken substantially along lines 33 of Fig. 1;

Fig. 4 is an enlarged elevational view of a valve member shown in Fig. 1;

Fig. 5 is an enlarged elevational view of a valve stop member shown in Fig. 1;

Fig. 6 is an enlarged elevational view of a timing valve plunger shown in Fig. 1;

Fig. 7 is a schematic view of the invention with the elements thereof in position prior to fuel injection taking place;

Fig. 8 is a schematic view similar to Fig. '7 after fuel injection has begun; and

Fig. 9 is a schematic view similar to Figs. 7 and 8 after completion of the fuel injection and prior to return of the operating elements to normal position.

Referring more particularly to the drawings. the invention is shown embodied in a fuel injector or pump comprising a body ll) of generally rectangular cross section in both its longitudinal and transverse dimensions and adapted to be attached to an internal combustion engine, for example by means of bolts 20. The fuel injector as shown is of the dual injection type in which fuel is supplied to the injector through a single conduit and two separate pulses of fuel are ejected therefrom with a single movement Of an engine-actuated cam. Separate fuel: metering meansand separate valve means are provided to produce the two pulses of fuel with common fuel injection timing means and common means for regulating the amount of fuel ejected.

Extending longitudinally inwardly from the right end of body ID are the parallel bores ll, l2 and I3 (Figs. 1 and 3), the bore I! being sub- .stantially central of the body and forming a source of fuel under pressure, the bores H and I 3 being laterally spaced from bore I 2 and containing the fuel ejection mechanisms. Extending longitudinally inwardly from the left end of body [0 and in alignment respectively with bores H and I2 are parallel bores i4 and I5, the bore I4 containing the valve mechanism controlling the ejection of one fuel pulse and bore l5 together with bore l2 containing the mechanism for timing the-fuel ejections. The injector body includes another bore, not shown, corresponding; to bore H and in alignment with bore I3 to house a second valve mechanism similar to that in bore l4 thereby to provide separate valve mechanisms for producing two fuel injections simulta-' neously from a single source. Bore l2 at its right end is closed by a timing valve barrel retainer 16 held to injector body ill by screws I I, a fuel supply conduit l8 being connected to retainer l6 by means of a flange nut It! to supply fuel under pressure. The fuel conducted to bore I2 is transmitted through passageways to mechanisms in bores II and I2 for effecting fuel ejection and is transmitted through other passageways to mechanisms in bores l4 and I5 for preventing valve actuation except at the instant fuel injection is desired and for replenishing the fuel in the metering chambers, as will be explained. The left end of bore H, as well as the valve mechanism bore corresponding to bore i3, is closed by fuel discharge connectors 2| attached to the fuel injector body by screws 22 and provided with passageways connected to conduits 23 by the flange nuts 24 to conduct fuel to injection nozzles 25 (Figs. 7 to 9).

Central bores I2 and i are separated by an internal shoulder 26 forming a fixed position within the injector so as to properly space the operating elements therein. Abutting against the right edge of shoulder is a timing valve barrel 21 provided with a central bore extending the full length thereof and in which the timing valve plunger 28 is adapted to move. Abutting the right end of timing valve barrel 21, there is a spacing member 29 and abutting this member through a metal sealing ring 32 is the fuel supply barrel 3|. The fuel supply barrel 3| is held in position by the timing valve barrel retainer l3 through a metal sealing gasket 33, thereby holding timing valve barrel 2! in position. The metal sealing rings seal each end of supply barrel 3| not only between the members abutting it, but

also between the supply barrel and bore l2, since the supply barrel has a conical surface at its left end and valve barrel retainer It has a conical surface abutting sealing gasket 33 which, when element i6 is screwed to injector body It, forces the sealing members outwardly against bore l2. The various members inside of bore l2 are formed with appropriate diameters and finished surfaces so as to be just easily receivable within the bore.

'Fuel is continually supplied; under high pressure to the inside of barrel 3| which forms a fuel supply chamber from whence the pressure thereof is transmitted through a. series of radial holes 34 against one side of pistons 35 arranged to operate within bores H and I3, and fuel to be ejected is supplied to the other side of pistons 35 through conduits or passageways extending from chamber 30 to bore l4. Chamber 30 forms a'substantially uniform supply of high pressure fuel for optimum operation at all speeds and loads since the source of fuel may be several feet away from chamber 30 and connected thereto through this length of conduit l8.

Bores ii and I4 are separated from each other substantially centrally of body In by an internal shoulder or wall 38. Immediately abutting the right surface of wall 38 is a piston stop plate 31,

.and abutting stop plate 31 there is a metering piston barrel 38 having a longitudinal bore therethrough in which piston 35 is adapted to move. Spaced longitudinally of metering piston barrel 38 by a metal sealing gasket 39 is the piston stroke control shaft guide 4|, and abutting the piston stroke control shaft guide through a metal sealing gasket 4|! is a pinion shaft guide 42 provided with a central bore through which the pinion shaft 43 is adapted to pass. Pinion shaft guide 42 includes a circular shoulder against which the inner end of retainer sleeve 44 abuts, the retainer sleeve being held to body it by screws 45. thereby holding piston stop plate 31,

hand position. Piston portion 48, the inside diameter of metering piston barrel 38, the left end of piston 35 and the piston stop plate 31 form a discharge chamber adapted to be filled with fuel oil, a portion of which is ejected therefrom when piston 35 is moved toward the left to abut against piston stop plate 31, diagonally converging holes being provided in piston portion 46, as shown, to permit easier fiow of fuel out of the discharge chamber. Piston 35, biased by spring 41, abuts the piston stroke control stop 48 which includes an externally threaded sleeve member received in corresponding threads in piston stroke control shaft guide 4|. By rotating piston stroke control stop 48, this being accomplished by rotating the pinion shaft 43 connected to piston stop 48 by a splined coupling 49, the position of piston 35 is determined.

Adjacent the right end of piston 35, the bore in metering piston barrel 38 is enlarged, thereby providing in cooperation with piston stroke control shaft guide 4| and piston stop 48 a pistonactuating chamber 60 into which oil under high pressure is received for moving the piston until it abuts the stop plate. Fuel under pressure is supplied to piston-actuating chamber 60 through the passageway 5| communicating with the source of fuel through openings 34 and the circumferential groove on piston stroke control shaft guide 4|, the circumferential groove communicating in turn with the piston actuating chamber by means 01' diagonal passageways 52. Accordingly, there is a continuous passageway from the rear surface of piston 35 to the inside of chamber 30 so that whenever the fuel injector is in operation there will be fuel pressure exerted against the base of piston 35 thereby urging it toward the fuel ejection position, actual movement except at the proper time being prevented by valves to be demetering piston barrel 38, piston stroke control scribed. The high pressure of fuel in the pistonactuating chamber is confined by means of the metal sealing gaskets 39 and 40 which are forced radially outwardly by means of the angular surfaces on guide members 4| and 42 a utting t em.

The rotation of pinion shaft 43 to produce variations in the position of piston stop 48 is accomplished through the pinion gear 53 and the toothed rack 54 (Fig. 3), the toothed rack being slidably arranged in a transverse bore within body l0. Gear 53 is relatively loosely received over a pinion hub 55 and is tightly held thereto by a pinion retainer 56 (Fig. 1) which is held to the pinion hub 55 by means of a series of screws 51. Pinion hub 55 is fixed rotatively as well as axially relative to pinion shaft 43 by means of a Woodrufi' key 58 and the transverse pin 10. The right end of pinion shaft 43 is provided with a spherical bearing surface which abuts against a steel ball 59, the steel ball being received within a spherical bearing surface in the thrust-adiusting screw 6| threaded into a retainer sleeve block 62, in turn threaded into retainer sleeve 44. The screw 6| may be turned to any position thereby determining the position of pinion shaft 43 and may be held fixed in this position by means of the jam nut 63. When the fuel injector is in use, the high pressure in piston-actuating chamber 60 is also exerted against the left end of pinion shaft 43, forcing the pinion shaft tightly against ball bearing 59. Hence if it becomes necessary during the operation to rotate shaft 43 for adjusting the initial position of piston 35, this may be done by moving rack 54 in the proper direction without having the end of pinion shaft 43 exert a high resisting frictional force, the ball bearing 59 providing a. relatively friction-free contact.

Referring to Fig. 3, it will be seen that in bore l3, corresponding to bore ll, there is a retainer sleeve 64 and a centrally extending pinion shaft 65 to which is keyed a pinion hub 66 supporting a ring gear 6'! engaging another portion of toothed rack 54 for producing adjustment of a second fuel discharge chamber in synchronism with fuel discharge chamber 60. Pinion hub 66 is keyed to shaft 65 similarly to pinion hub 55 and shaft 43. The valve mechanism controlling the ejection of fuel from the'discharge chamber includes a pair of valves H and 16 arranged in series within bore l4 to the left of shoulder 36, the two valves being slidahle respectively within central bores of the valve guides 69 and 15. Valve guide 69 abuts the reloading valve seat 68 which abuts the left side of internal shoulder or wall 36, valve seat 68 having a central passageway therethrough as well as a series of angularly extending passageways laterally spaced from the central passageway, the angularly extending passageways communicating with circular grooves on each side of the valve seat. Valve guide 69 includes a longitudinal passageway 12 communicating with a circular groove at the right end of the valve guide which registers with a corresponding circumferential groove in valve seat 66. At the other end of passageway 12 valve guide 69 is provided with a circular cut-out portion forming a chamber 73 into which one end of valve body 1| projects. Spaced between valve guides 69 and I is a valve seat 14 having a central opening for communicating with chamber 13 and adapted to be covered by the left end of valve body I l, the central opening connecting with a circular groove at the left end of valve seat 14 through a series of angularly extending passageways. Valve guide 15, similar to valve guide 69, includes a longitudinal passageway Tl communicating at one end thereof with a circular groove registering with a corresponding circular groove in valve seat 14 and communicating with a circular cut-out portion forming a chamber 18 at the other end thereof. Abutting the left end of valve guide 15 is a valve seat 19 including a central passageway for communicating with chamber 18 and adapted to be closed by the left end of valve 16, the passageway also communicating with the passageway in fuel discharge connector 2 l.- The fuel discharge connector abuts valve seat 19 through a metal sealing gasket 8|, thereby holding the various members within bore [4 and forming a fluid-tight connection from the inside thereof to the exterior.

The valves H and 16 are identical with each other and, as shown in Fig. 4, each includes a relatively long cylindrical portion 82 for guiding these members in the valve guides. At the right end of the valves there is a head portion 83 and at the left end there is a sealing surface 84, the surface 84 being very accurately machined and finished. The surfaces of valve seats 14 and 19 are also very accurately machined and finished so that when the surfaces'84 are against the valve seats an accurate fit is obtained and fuel cannot pass therebetween into the passageways. In order to produce the desired functioning of the valves, the area of surface 84 is considerably smaller than the cross-sectional area of portion 82 and thus smaller than the head 83 thereof.

Valves H and 16, when positioned within the corresponding bores of valve guides 69 and 15, have their left ends (surfaces 84) disposed within chambers 13 and I8, respectively, and have their heads 83 disposed within enlarged portions of the bores forming chambers 92 and 94. Within chamber 92 between the valve seat 68 and the valve 16 may move from a closed to an open position, a spring 88 being arranged, as shown, to

bias valve I6 to its closed position. Referring to Fig. 5, the valve stop is shown as including a central bore or passageway 99 communicating with the exterior of the valve stop through radially extending bores 9|. The valve stop 91 is similar to stop 85 except that it is not provided with passageways 89 and 9|.

Chamber 92 communicates by means of a radial bore in valve guide 69 and a circumferential groove, as shown, with a passageway 93 in body i0, and chamber 94 communicates through a radial bore in body 15 and a circumferential groove thereon, as shown, with a passageway 95 in body to. Fuel pressure is supplied through passageways 93 and 95 respectively to chambers 92 and 94, thereby urging valve bodies H and 76 to their closed positions. The passageway 93 also communicates with the discharge chamber 59 through the passageways 9| and 89 in valve stop 85, the central passageway through valve seat 68 and the bores in the internal shoulder 36 and piston stop plate 31. This passageway fills the discharge chamber with fuel and to close the passageway during the ejecting operation a disc reloading valve 96 is arranged to abut the right side of valve seat 68, the reloading valve being urged toward passageway closed position by means of the coil spring 91. Reloading valve 96 is somewhat smaller than the bore through shoulder 36, whereby the fluid passageway out of the discharge chamber is unimpaired. Passageway 12 in valve guide 69 being in communication with the chamber 13 and with the discharge chamber 50 through the angularly extending bores in valve seat 68 and the bore through shoulder 36, whenever there is fuel in the discharge chamber and the various passageways are filled with fuel, the fuel pressure in chamber 13 urges the valve ll toward an 'open position. This urging is resisted by the fluid pressure within chamber 92 acting against the head of the valve communicated thereto through passageway 93.

The passageway from discharge chamber 50 to the conduit 23 leading to the injection nozzle may be closed at one point by the valve H abutting its surface 94 against valve seat 14. When valve H is open, passageway 11 in valve guide 15 communicates withpassageway 12 through the angularly extending bores in valve seat 14 and chamber 13 in valve guide 69, and hence communicates with discharge chamber 50. Since passageway 11 communicates with chamber 18 and thence with conduit 23 through the bore in valve seat 19, there is a complete passageway from conduit 23 to discharge chamber 58 when valves II and 16 are in their open position. When valve 16 is in its closed position, i. e., its left end abuts valve seat 19, the passageway from the discharge chamber to the conduit 23 is closed at another point,

thereby closing this passageway at two points to effectively prevent the leakage of fuel therethrough. The fuel pressure in chamber I8 urges valve I6 toward its open position, this being resisted by the fuel pressure within chamber 94 communicated thereto through passageway 95. when valve II opens, the pressure of the fuel in discharge chamber is exerted against the left end of valve I6, thereby urging it to the open position.

Fuel in the discharge chamber is under pressure at all times by virtue of the fuel pressure behind piston 35, and this fuel pressure is continually exerted against the left end of valve body II. Piston 35 includes a series of circum ferential grooves as shown, one or more of which communicates with radial holes in barrel 38 and thence with conduit 89 whereby fuel leakage into the remaining mechanism from chamber 69 is prevented. Whenever the pressure is released in chambers 92 and 94, the pressure being exerted by the piston in the discharge chamber acting against the valve bodies 'II and IS in chambers 13 and 18 immediately forces the valve bodies to their open positions to permit the ejection of fuel through a continuous passageway from the discharge chamber to nozzles 25.

The movement of valves II and I6 to their open positions, except during ejection, is prevented by fuel pressure alone, and the opening movement is effected by fuel pressure alone when the preventing fuel pressure is released by timing apparatus. The manner of obtaining these pressures may now be described.

Timing valve barrel 21, in addition to its central bore in which timing valve 28 is arranged to move, includes an angularly extending passageway 99 communicating with a circular groove at the right end of timing valve barrel 2'! thereby communicating with the inside of fuel supply chamber 39 through the longitudinally extending bores in spacing member 29. The other end of passageway 98 communicates with an internal circumferential groove spaced a relatively short isfance from the radial bores 99. Radial bores 99 communicate with a circumferential groove on the outside of timing valve barrel 21, which is of suflicient extent to be in communication with both passageways 93 and 95. The timing valve plunger 28 includes an external circumferential channel I9I of sufficient extent to connect both the radial bores 99 and the passageway 98 throu h the internal circumferential groove at its left end. Accordingly, when valve plunger 28 is in the position shown in Fig. 1, there is a continuous passageway from fuel supply chamber 39 to the chambers 92 and 94 through the passageways in spacer 29, the passageway 98, groove I9I the radial bores 99, and the passageways 93 and 95 respectively. Consequently, the high fuel pressure from the source through conduit I8 is ex rted against the heads 83 of valves II and I6 in chambers 92 and 94. The high pressure of the fuel in discharge chamber 59 is also being exerted in chamber I3 against the left end of valve II, but when valve II is closed, that is, its surface '24 is against the corresponding surface of valve seat 14, the high pressure fuel cannot get behind surface 84. Accordingly, the pressure exerted by the high pressure fuel from the discharge chamber tending to open the valve is exerted only a ainst the difference in the areas of surface 84 and the cross section of the valve body 92 (Fig. 4). Since the fuel pressure in chamber 92 is being exerted against an area on the head of the valve equal to cross-sectional area of portion 82, it is apparent that the fuel pressure will main tain valve II closed. Similarly, fuel pressure from chamber 39 is exerted through conduit against the head of valve 19 on an area corresponding to the cross section of its body. The pressure in passageway 11 is exerted against the left end of valve I6 upon an area also equal to the difference between the area 94 and the crosssectional area of portion 82, since fuel under high pressure cannot getbehind surface 84 when valve I9 is closed and the greater pressure is exerted against the head of valve 16 thereby maintaining this valve closed against the pressure in passageway TI. Thus, while high fuel pressure is being exerted against the left end of valve 'II and fuel pressure in passageway I1 is exerted against the left end of valve I6, these valves are maintained closed by the fuel pressure in chambers 92 and 94.

Valve punger 28 includes a central passageway I92 (Fig. 6) and an angular groove I93 cut around the surface thereof, the bottom of the groove communicating through a hole I94 with the bore I92, the bore I92 also communicating with the inside of bore I5 through radial passageways I95. Whenever it is desired to produce a fuel ejection, that is, at the proper time interval, the plunger 28 is moved toward the right until the groove I93 comes into registry with the radial bores 99. When this occurs, there is a completed passageway from chambers 92 and 94 through passageways respeetively 93 and 95, radial bores 99, angular groove I93, hole I94, longitudinal bore I92, and radial bores I95 to bore I5, thereby relieving the pressure within chambers 92 and 94. The circumferential channel I9I on plunger 28 is spaced sufficiently away from angular groove I93 so that when plunger 28 is moved toward the right, the connection between passageway 99 and radial bores 99 is closed by the valve plunger, thereby cutting oil the pressure of fuel to chambers 92 and 94. Hence when groove I 93 comes into registry with radial bores 99, allowing the oil therein to flow out to relieve the pressure in chambers 92 and 94, the pressure within the bore I2 does not affect the operation.

The oil removed from chambers 92 and 94 during the ejection operation passes into bore I5 through the various passageways and is drained from the injector through a passageway I2I. In order to prevent any of the oil finding its way into bore I5 from coming out rearwardly thereof, the bore I5 is closed by an oil baffle I22 held within the bore by means of a snap ring I23.

The left end of timing valve barrel 2! projects a considerable distance into bore I5. Surrounding this projecting portion of barrel 2'! and abutting against the left side of internal shoulder 26, is a pinion sleeve I99 having a bearing surface on the timing valve barrel so as to be rotatable thereon. The right end of pinion sleeve I96 is provided with gear teeth around its circumference, which gear teeth are engaged with corresponding gear teeth on a timing rack I91 vertically movable in a guide slot in body I9 as shown. Adjacent the left end of pinion sleeve I96 there is a 'slot or cut-out portion formed therein into which the projecting tongue I98 of timing valve guide I99 is received, the valve guide being rigidly attached to the timing valve plunger 28. Tongue I98 is slidably received in the cooperating groove in pinion sleeve I96 so that when rack I9! is moved vertically to rotate pinion sleeve I95, the timing plunger 28 is also rotated. Since slot I93 is angularly disposed relative to the axis of valve plunger 28, rotation thereof brings a different portion of. angular slot I03 into registry with radial bores 99 when the valve plunger is moved toward the right, this efiecting a variation in the time at which fuel ejection'occurs. The timing valve guide I09 is rotatively and axially fixed to the timing valve plunger by means of a Woodruff key III! and pin III (Fig. 2

In order to bias timing valve plunger 28 to its outward position, shown in Fig. 1, a valve spring H2 is arranged withinbore I to abut a valve seat H3, and a timing valve spring collar II4 which is held to the shaft of timing valve plunger 26 through a head on the shaft and a cooperating shoulder on the collar. The valve seat H3 projects inwardly a sufiicient distance to hold pinion I06 in its inward position. Surrounding valve spring H2 and collar H4 is a timing valve spring cap I I5 of a diamcter to be easily received within bore I5, the spring cap H5 including a spherical bearing surface at its left end into which a corresponding spherical bearing surface on a rocker link H6 is received. The other end of rocker link II6 includes a spherical bearing surface received within a cooperating spherical bearing surface at one end of a tappet member 1, the tappet member being pivoted to injector body III on a shaft H8. The tappet member is adapted to be rocked backwardly and forwardly through a rocking cam H9 operated from an engine in any manner such as is well understood in the art. The cam H9 has a curved surface I20 bearing directly against one end of tappet member II1 to produce rocking motion thereof. Thus when cam H8 is in the position shown in Fig. 2, timing valve plunger 28 is in its extreme left hand position, and when cam I ID has rotated counterclockwise, the timing valve plunger will be in its right-hand or ejection position.

The upper end of tappet H1 is enc osed by means of a cap I24 held to valve body III by appropriate screws Arranged to overlie injector body III adjacent its right end so as to cooperate with rack 54 to produce adjustment in the capacity of the discharge chambers, is the governor mechanism I25 (Fig. 3) comprising a housing having a transpinions 53 and 31 thereby producing variations verse bore I26 adapted to be closed at one end is reciprocoble within bore I26, the governor piston being hollow and receiving a coil spring I32 therein abutting the right end thereof. At the other end of piston I3I there is a cross head I33 provided with a cross pin I34 to which the piston arm I35 is pivoted. Cross head I33 abuts spring I32, whereby the spring normally maintains this member in the position shown in Fig. 3, the cross head being prevented from coming out of piston I3I under the influence of spring I32 by virtue of snap ring I36 received within a cooperating groove in piston I3I. Cross head I33 is movable within the piston and to permit this movement piston I3I is provided with a slot or cut-out portion I31 within which the piston arm I35 adapted to move. On the side of piston I3I, opposite to slot I31, gear teeth I38 are arranged as shown and a pinion gear I4I supported in governor housing I25 on a shaft I39 engages gear teeth I38 and the toothed rack 54. Accordingly, when piston I3I is moved in one direction or the other, the pinion I is rotated to effect movement of gear rack 54 and hence movement of in the initial position of the ejection pistons 35.

The initial setting of piston I3I, and thereby the desired discharge chambers capacity, is accomplished by moving the indicator I42 to any position along scale I43 indicating the fuel capacity. Indicator I42 is attached to a shaft I44 supported in housing I25, the piston arm I35 being also attached to shaft I44, whereby moving the indicating arm varies the position of piston I3I.

Bore I26, needle valve body I29, and the right end of piston I3I form a chamber I45 to which fuel pressure may be supplied from a conduit I46 through passageway I49. In the position shown, fluid pressure exerted against piston I3I would not produce any variation in the position thereof. However, supposing the position of piston I3I is that indicated by broken line I48, fluid pressure exerted against the base of piston I3I would force it to move toward its left-hand position (cross head I33 remaining stationary) and thereby change the position of piston I3I from that determined by the setting of arm I42. Arm I42, once it has been set in a desired position, is held in that position by any desirable means and does not move when fluid pressure is exerted against the base of piston I3 I. This may occur by virtue of the fact that cross head I33 is movable within piston I3I. When there is fluid inside of chamber I45 and piston I3I has been moved toward the left, coil spring I32 is compressed and urges piston I3I toward its right-hand position or that determined by the setting of arm I42. Hence the fuel in chamber I46 is placed under pressure. Fuel may flow out of chamber I45 through a passageway including a valve seat insert I52 to an exit conduit I5 I. A conical-ended needle valve I53, whose position may be varied relative impulse flows out through conduit I5I under the influence of spring I32 urging piston I3I toward its original position, the rate of return being determined by the position of needle valve I53.

The function of the governor mechanism to vary the position of piston I3I after its initial setting by arm I42 is more completely described and claimed in a co-pending application entitled Free Piston Engine, Fuel Control, Serial No,

781,426, filed October 22, 1947, in the name of Louis J. Garday, and which application is assigned to the same assignee as the present invention.

With the foregoing structure and function of individual elements in mind, the coordinated operation of the fuel injector may best be understood and additional structure disclosed by referring to the schematic diagrams of Figs. '7 to 9 in which reference numerals corresponding to those of the other figures are used.

In Fig. 7 the injector and its elements are shown in a quiescent position. That is, rocker link H6 is in its completely outward position whereby spring II2 has urged valve plunger 28 to its extreme outward position interconnecting passageways 98 and 99; conduit Ia being connected to a source of high pressure fuel, chamber 30 is filled with high pressure fuel; high pressure from fuel inchamber 39 is being exerted through conduit against the rear surface of metering piston 85 in chamber 80, the initial position thereof shown having been predetermined by moving rack It to the desired position which, through gear 53, has rotated shaft and consequently piston stop 49; high pressure from chamber is is exerted against base of piston 35 in discharge chamber 80 through passageway 98, groove Ilil, passageways 98, 93 and 88; the oil pressure being substantially equal on both sides of piston 35, the piston has moved to its rest position by virtue of spring 41, and discharge chamber 59 is filled completely with oil; reloading valve 99, while biased to close the central passageway through valve seat 58, was lifted off its seat to allow the discharge chamber to flll with oil, and since this has occurred the fluid pressure on each side of valve 95 is substantially the same, whereby spring I. has caused valve 85 to close the passageway through valve seat 69; the passageway I2 and chamber II are fllled with high pressure fuel since these passageways are in direct communication with discharge chamber 59; valve body II has closed the passageway through valve seat It because of the spring 88 and remains closed because high fluid pressure from passageway 98 acts against the head of the valve and the high pressure in chamber 13 is directed against a smaller area; valve 16 has closed the passageway through valve seat 19 because of spring 88 and remains closed because the high fluid pressure from passageway 95 acts against the head of the valve and the pressure in chamber I8 is directed against a smaller area; and assuming that a previous fuel election has occurred, the passageway 11, the passageway in member 2i and the conduit 23 are completely filled with oil which will be under a low pressure (that existing after a fuel injection has occurred). this relatively low pressure being exerted against the left end of valve I8 within chamber 18. Hence, the high pressure existing in discharge chamber 58 is kept from the discharge nozzle 25 by both valves II and it. As has already been explained, the area at the head of the valves is substantially greater than that existing at the front ends of the valves so that the difference in force due to fluid pressure acting upon the diiferential areas is sumcient to maintain the valves closed even against the high fluid pressure from the discharge chamber. Rack III! has been moved to a position where the angular groove I93 in valve plunger 23 is in the position desired.

The injection nozzle 25 includes a valve plunger I86 held against the valve opening by means of a spring I51.

In Fig. 8 the injector and its elements are shown in their position a short time interval after Fig. 7 and fuel ejection is in progress. That is, rocker link II6 has moved valve plunger 28 to the right thereby bringing angular groove I01 into registration with passageway 99, and also closing on passageway 98 which in Fig. 4 was connected to passageway 99 through groove IOI angular groove I93 has connected the exterior of injector body I 9 through passageways III and I92 with passageway 99 whereby the oil in chamhers 92 and 94 has leaked out and thus relieved the high pressure existing on the heads of valves II and 19; since the high pressure in discharge chamber was still exerted through passageway I2 and chamber I3 against the left end of valve II, this valve has been lifted off its seat against assesses the force of spring 89; this same high pressure being also exerted against valve 89, this valve is tightly forced against its seat and hence prevents leakage of high pressure fuel from discharge chamber 58 through passageway 99; consequently, the high pressure in discharge chamber 50 has been transmitted through passageway 11 and chamber it against the left end of valve I6; since the pressure on the head of valve 11 has been relieved, the high pressure exerted against the left end thereof has lifted this valve on its seat also; and there now being a clear passageway from discharge chamber III to the injection nozzle 25, the high pressure exerted by the fuel in chamber against piston 35 has forced the fuel to exert pressure through the continuous passageway against valve I56 and has lifted this valve ofl its seat. Under the influence of fuel pressure from chamber 60, piston 35 has completed a partial stroke to eject a portion of the fuel, the piston continuing to move until it contacts the stop. The stiffness of spring I5! is so chosen that the pressure to lift valve I58 of! its seat is greater than the closing pressure of valves II and I6. Accordingly, while fuel is being injected, valves II and I6 remain open until all the fuel has been injected.

If plunger 28 had been rotated to a different position by the rack I91, the angular slot I03 would have come into communication with .passageway 99 a short interval sooner or later, depending on the direction of rotation. With rocker link H8 operating in fixed relationship to the engine, it is apparent that rotating the groove I93 varies the timing of fuel injection.

In Fig. 9 the fuel injector and its elements are shown in their positions following the completed fuel injection with the elements approaching their positions to place the apparatus in a condition for the following ejection. That is, metering piston 35 has moved to its extreme left-hand position with all of the fuel out of the discharge chamber 59; and the valves II and I6 have moved to their seated positions under the influence of springs and 88 respectively. This occurs because after fuel injection occurs through nozzle 25 the pressure in conduit 28, as well as in passageways I1 and 12, decreases to a relatively low value, thereby decreasing the fuel pressure urging the valves toward their open positions to such an extent that the springs exert sufficient force to close them. The valve plunger 28 has moved toward its left-hand position due to spring I I2 under continued engine operation to a point where the angular slot I03 is no longer in communication with passageway 99 and the channel IIlI is on the verge of connecting passageways 99 and 98. At this point, the fuel pressure in passageways 93, and 99 is still low by virtue-of the fact that the high pressure was relieved (Fig. 8) and the high pressure from chamber 60 is still being exerted against the rear face of piston 35. Due to the decrease in fuel pressure in nozzle 25, the plunger I56 has taken its seat under the influence of spring I51.

An instant following the conditions shown in Fig. 9, continued operation of the injector moves plunger 28 further to the left from the position shown in Fig. 9 to that shown in Fig. 7, thereby connecting passageways 98 and 99. Hence, the high pressure in chamber 38 is again exerted through passageways 98, 89, 93 and 95 against the heads of valves 1| and I6, thereby forcing these valves tightly against their seats. Under this high pressure, the fuel flows through the passageways named and flows through passageway 89 in piston stop. 85 lifting the valve 88 off its seat against spring 91 (the fuel pressure opposing movement of valve 96 is low), thereby permitting the fuel to exert high pressure through the passageways named and the discharge chamber 50 against the base of piston 35. Since the same high pressure is now exerted against both sides of metering piston 35, the spring 41 returns the metering piston to its initial position and the discharge chamber fills with high pressure fuel. At the same time, the high pressure is exerted against the left end of valve ll through passageway 12 and chamber 13, but the high pressure being also exerted against the head of valve II, this valve remains tightly closed. After the discharge chamber 50 is filled with fuel, high pressure is exerted against both sides of valve 96 and this valve moves to its closed position under the influence of spring 91. Accordingly, the parts are in the position shown in Fig. 7 and are ready for a repeat operation.

The time of fuel injection during operation is small and some lag is produced by the friction and inertia of the parts and the fuel. A complete fuel injection must occur before timing plunger 28 brings channel llll into registry with passage 99 at which time fuel injection ceases due to the closure of valves 1| and 16. Comparing Figs.- 8 and 9, it will be seen that valve plunger moves a distance toward the left equal to the distance between angular groove I03 and channel llll before fuel injection ceases after initiation thereof. This gives rise to a time interval during which complete injection occurs.

While I have shown a particular embodiment of my invention, it will be understood, of course, that I do not wish to be limited thereto since many modifications may be made, and I, therefore, contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A fluid operated fluid injector comprising a body including a passageway therein adapted to be connected to a source of fluid under pressure at one end and forming a discharge opening at its other end, a pair of movable valve bodies for opening and closing said passageway at two points, means for subjecting each of said valve bodies to opposed fluid pressures derived from said source of fluid, differential areas on each of said valve bodies responsive to said opposed fluid pressures to hold each of said valve bodies in a closed position, and means for simultaneously relieving the fluid pressure from one area of each of said valve bodies while exerting fluid pressure on the other area of each of said valve bodies whereby said valve bodies move to open positions.

2. A fluid operated fluid injector comprising a body including a fluid measuring chamber adapted to communicate with a source of fluid under pressure, a passageway in said body communicating with said chamber at one end and forming a discharge orifice at its other end, a piston movable in said chamber under the influence of fluid pressure from said source to eject fluid from said measuring chamber through said passageway, a movable valve body in said passageway adapted to be subjected to opposed fluid pressures derived from said source, differential areas on said valve body responsive to said opposed fluid pressures to hold said valve body 14 in a closed position, and means for relieving the fluid pressure from one of said areas while substantially maintaining the fluid pressure on the other of said areas, whereby said valve body gloves to an open position to effect said fluid ejec- 3. A fuel pressure operated fuel injector comprising a body including a passageway therein adapted to be connected to a source of fuel under pressure at one end and forming a discharge opening at its other end, a pair of movable valve bodies for opening and closing said passageway at two points, means for. subjecting each of said valve bodies to opposed fuel pressures derived from said source of fuel, differential areas on each of said valve bodies responsive to said opposed fuel pressures to hold each of said valve bodies in a closed position, and means for relieving the fuel pressure from one area of each of said valve bodies while exerting pressure on the other of saidareas, whereby said valve bodies are moved to open positions.

4. A fuel pressure operated fuel injector comprising a body including a fuel measuring chamber adapted to communicate with a source of fuel under pressure for filling said chamber. a passageway in said body communicating with said chamber at one end and forming a discharge opening at its other end, a piston movable in said chamber under the influence of fuel pressure from said fuel source to eject fuel from said measuring chamber through said passageway, a movable valve body in said passageway adapted to be subjected to opposed fuel pressures derived from said source of fuel, differential areas on said valve body responsive to said opposed fuel pressures to hold said valve body in a closed position, and means for relieving the fuel pressure from one of said areas while substantially maintaining said fuel pressure on the other of said areas, whereby said valve body moves to-an open position to effect said fuel ejection.

5. A fuel pressure operated fuel injector comprising a body including a fuel measuring chamber adapted to communicate with a source of fuel under pressure for filling said chamber, a passageway in said body communicating with said chamber at one end and forming a discharge opening at its other end, a piston movable in said chamber for exerting pressure on one side to eject fuel from said chamber through said passageway, means for communicating fuel pressure from said source to the other side of said piston to effect said fuel ejection, a pair of movable valve bodies for opening and closing said passageway at two points, means for subjecting each of said valve bodies to opposed fuel pressures derived from said source of fuel, differential areas on each of said valve bodies responsive to said opposed fuel pressures to hold said valve bodies in closed positions, and means for relieving the fuel pressure on one of the areas of each of said valve bodies while exerting fluid pressure on the other area of each of said valve bodies whereby said valve bodies move to open positions.

6. A fuel pressure operated fuel injector comprising a body including a passageway for conducting fuel derived from a source of fuel under pressure, a pair of valve bodies movable to open and close said passageway at two points, differential areas on each of said valve bodies, the lesser one of the differential areas on each of said valves being adapted to be subjected to the pressure of the fluid in said passageway for urging said valve bodies toward open positions, means for subjecting the other of the differential areas of each of said valve bodies to an opposing fuel pressure derived from said source of fuel under pressure, said differential areas and the pressures thereon cooperating normally to close said passageway, and means for relieving the pressure from each of said other areas while maintaining the pressure in said passageway, thereby to move said valves to open positions.

7. A fuel pressure operated fuel injector comprising a body including a fuel measuring chamber adapted to communicate with a source of fuel under pressure for filling said chamber, a passageway in said body communicating with said chamber at one end and forming a discharge opening at its other end, a piston movable in said chamber for exerting pressure to eject fuel from said chamber through said passageway, means for transmitting fuel pressure from said source to one side of said piston to effect said fuel ejection, a pair of movable valve bodies for closing said passageway at two points for preventing fuel ejection, differential areas on said valves, means for subjecting the lesser one of the differential areas on each of said valves to the fluid pressure in said passageway to urge said valve bodies to open positions, means for subjecting the other of the differential areas of each of said valve bodies to the pressure of said source of fuel urging said valve bodies to closed positions, whereby said differential areas are responsive to the pressures exerted thereon to normally hold said valve bodies in a closed position, means for relieving the pressure against the other differential surfaces of each of said valves while exerting pressure on the lesser of said differential surfaces thereby to move said valve bodies to open positions.

8. A fuel pressure operated fuel injector comprising a body including a fuel measuring chamber adapted to communicate with a source of fuel under pressure for filling said chamber, a passageway in said body communicating with said chamber at one end and forming a discharge opening at the other end, a piston movable in said chamber, means for varying the initial position of said piston to vary the capacity of said measuring chamber, meansfor normally transmitting fuel pressure from said source against said piston thereby exerting pressure on the fuel in said chamber and passageway, valve means having differential areas responsive to the fuel pressure in said passageway and the fuel pressure from said source for normally closing said passageway to prevent flow of fuel therethrough, and means for relieving the source fuel pressure from said valve means while maintaining said passageway fuel pressure, thereby effecting valve response to open said passageway and permit the ejection of fuel from said measuring chamber.

9. A fuel pressure operated fuel injector comprising a body including a fuel measuring chamber adapted to communicate with a source of fuel under pressure for filling said chamber, a passageway in said body communicating with said chamber at one end and forming a discharge opening at the other end, a piston movable in said chamber, means for varying the initial position of said piston to vary the initial capacity of said measuring chamber, means for causing said varying means to change the initial position of said piston set thereby, means for normally transmitting fuel pressure from said source against said piston thereby exerting pressure on the fuel in said chamber and passageway. valve means having opposed differential areas responsive to the fuel pressure in said passageway and the fuel pressure from said source for normally closing said passageway to prevent flow of fuel therethrough, and means for relieving the source fuel pressure from said valve means while maintaining said passageway fuel pressure, thereby efi'ecting valve response to open said passageway and permit the ejection of fuel from said measuring chamber.

10. A fuel pressure operated'fuel injector comprising a body including a fuel measuring chamber adapted to communicate with a source of fuel under pressure for filling said chamber, a passageway in said body communicating with said chamber at one end and forming a discharge opening at the other end, a piston movable in said chamber, means for normally transmitting fuel pressure from said source against said piston thereby exerting pressure on the fuel in said chamber and said passageway. valve means having opposed differential areas responsive to the fuel pressure in said passageway and to the fuel pressure from said source for normally closing said passageway to prevent flow of fuel therethrough, and timing means for relieving the source fuel pressure thereby effecting valve response to open said passageway and permit the ejection of fuel from said measuring chamber.

11. A fuel pressure operated fuel inJector comprising a body including a fuel measuring chamber adapted to communicate with a source of fuel under pressure for filling said chamber, a passageway in said body communicating with said chamber at one end and forming a discharge opening at the other end, a piston movable in said chamber, means for normally transmitting fuel pressure from said source against said piston thereby exerting pressure on the fuel in said chamber and said passageway, valve means having opposed differential areas responsive to the fuel pressure in said passageway and to the fuel pressure from said source for normally closing said passageway to prevent flow of fuel therethrough, and timing valve means including timing varying means for relieving the source fuel pressure from said valve means while maintaining said passageway fuel pressure, thereby effecting valve response to open said passageway and permit the ejection of fuel from said measuring chamber.

12. A fuel pressure operated fuel injector comprising a body including a fuel measuring chamber adapted to communicate with a source of fuel under pressure for filling said chamber, a passageway in said body communicating with said chamber at one end and forming a discharge opening at the other end, a piston movable in said chamber, means for varying the initial position of said piston to vary the capacity of said measuring chamber, means for normally transmitting fuel pressure from said source against said piston thereby to exert pressure on the fuel in said chamber and passageway, valve means having opposed differential areas responsive to the fuel pressure in said passageway and to the fuel pressure from said source for normally closing said passageway to prevent flow of fuel therethrough, and timing valve means including timing varying means for relieving the source fuel pressure from said valve means while maintaining said passageway fuel pressure, thereby effecting valve response to open said passageway and opening at its other end, a piston movable in said chamber, means for normally transmitting fuel pressure from said source against said piston thereby exerting pressure on the fuel in said chamber and passageway, a pair of valve chambers in said body, a valve body movable in each of said chambers for opening and closing said passageway at two points, spring means in each valve chamber urging said valve bodies to closed positions, said valve chambers opposite said spring end being in communication with said passageway whereby said valve bodies are subjected to the fuel pressures-in said pas ageway urging accuses said valve bodies to open positions, means for subjecting the spring ends of said valve bodies to the pre sure of the fuel from said source ur ing said valve bodies to closed positions, differential areas on each of said valve bodies responsive to said passageway and said fuel source pressures for normally closing said passageway to prevent flow of fueltherethrough, and means for relieving the sourcefuel pressure while continuing passageway fuel pressure on said valve bodies. thereby to move said valve bodies to open positions. v

14. A fuel pressure operated injector for injecting a mea ured quantity of fuel comprising a body including a fuel measuring chamber, a discharge passageway leading from said chamber and formin a discharge orifice, a piston movable in said chamber for ejecting fuel therefrom through said discharge passageway, means communicating fuel pressure from a source of fuel under pressure to said piston to effect movement thereof. a pas ageway adapted to connect said chamber and said source of fuel for filling thereof, means for clo ing said filling passageway, a valve chamber in said body, a valve body movable in said valve chamber for opening and closing said discharge passageway, one end of said valve chamber communicating with said passageway whereby the fuel pressure therein urges said valve body to an o en position, a passageway connecting the other end of said valve chamber to said source of fuel whereby said source fuel pressure urges said valve body to a clo ed position, differential areas on said valve body responsive to said discharge passageway and fuel source pressures to normally close said pa'ssageway, and valve means for closing said connecting passageway and thereafter opening a relief passageway to relieve the source fuel pressure from said valve body whereby said valve body moves to a discharge passageway open position under the influence of said discharge passageway pressure.

15. A fuel pressure operated injector for injecting a measured quantity of fuel comprising a body including a fuel measuring chamber, a discharge passageway leading from said chamber and forming a discharge orifice, a piston movable in said chamber for ejecting fuel therefrom through said discharge passageway, means communicating fuel pressure from a source of fuel 18 under pressure to said piston to effect movement thereof, a passageway adapted to connect said chamber and said source of fuel for filling thereof, means for closing said filling passageway, a

V valve chamber in said body, a valve body movable in said valve chamber for opening and closing said discharge passageway, one end of said valve chamber communicating with said discharge passageway whereby the fuel pressure therein end of said valve chamber and substantiallysimultaneously therewith connecting said relief passageway to said other end of said valve chamber whereby said valve body moves to a discharge passageway open position under the influence of said discharge passagewaypressure. I 16. A fuel pressure operated injector for injecting a measured quantity of fuel comprising a body including a fuel measuring chamber, a discharge passageway leading from said chamber and forming a discharge orifice, a piston movable in said measuring chamber for ejecting fuel therefrom through said discharge passageway, means for transmitting fuel pressure from a source of fuel under pressure to said piston to effect movement thereof, a passageway adapted to connect said measuring chamber to said source of fuel for filling said measuring chamber, valve means for closing said filling passageway, a pair of valve chambers in said body, a valve body movable in each of said valve chambers for opening and closing said passageway at two points, one end of each valve chamber communicating with said discharge passageway whereby the fuel pressures therein urge said valve bodies to open positions, a passageway extending from the other end of each of said valve chambers and connected with said source of fuel whereby said source fuel pressure urges said valve bodies to closed positions, differential areas on each of said valve bodies responsive to said discharge passageway pressures and said fuel source pressure to normally close said discharge passageway, a pressure relief passageway in said body, and valve means for disconnecting said source of fuel from said extending passageways and substantially simultaneously connecting said extending passageways to said pressure relief passageway thereby relieving the pressure in said valve chambers at said other valve body ends to effect movement of said valve bodies to open positions.

a LOUIS J. GARDAY.-

REFERENCES CITED The following references are of record in the file of this patent:

I UNITED STATES PATENTS Number Name Date 822,184 Chamberlain et a1. May 29, 1906 1,927,587 Hacker Sept. 19, 1933 2,040,667 Moulet May 12, 1936 2,333 944 Lieberherr Nov. 9, 1943 2,397,136 French Mar. 26, 1946 

